As is known, some handset devices, such as, mobile phones, personal digital assistants, and smart phones, comprise a slot intended to host an IC card or a flash memory card. For example, a mobile phone includes a slot for a Universal Subscriber Identity Module (USIM) associated to a subscriber line and to a corresponding phone number.
With reference to FIG. 1, a mobile phone schematically shown and indicated with numeral reference 1 comprises a slot 2 intended to host an IC card 3. A communication method between the mobile phone 1 and the IC card 3 is based on a standard communication protocol (ISO 7816) comprising a set of command Application Protocol Data Units (APDUs).
Sometimes, it is useful for a single user to have more than one USIM, each corresponding to a different phone number, generally associated to a different subscriber line.
For example, a first USIM is used for professional purposes and a second USIM is used for personal purposes, for foreign travels, for saving money with a cheaper rate, for accessing a network operator with different network coverage, or for using additional SIM Toolkit applications. It is also useful to have separated USIMs in order to distinguish different phonebooks and short message service (SMS) databases.
A communication method typically allows use of a single IC card at a time. In fact, according to such a communication method, a user may end a communication with a first IC card, in order to begin a communication with a second IC card, comprising the steps of: switching off the handset device, opening its cover, extracting the first IC card, substituting it with a second IC card, switching on the handset device, and establishing a communication with the second IC card.
More particularly, the slot inside the handset device is closed inside a handset cover, generally under a battery pack so that it is usually helpful to remove the handset cover and the battery pack to replace the IC card hosted in the slot. In this case, a user that needs to replace the IC card is involved in a laborious action.
It is also known that some handset devices, now neglected, were designed to host more than one IC card, generally in the back of the battery pack, in order to avoid an exchange as described above. Such a handset device was cumbersome because more than one IC card uses a lot of space inside the handset device in order to be hosted, the resulting size of the handset device being unsuitable to be carried in a the user's pocket.
Moreover, in such handset devices, a communication method between the IC card and the handset device provides that only one IC card at a time could be active, the operation of switching to the alternate IC card (usually done by powering the handset device off and on) may be an uncomfortable action. For this reason, new phone models that were smaller in size but not providing sufficient room for the battery and multiple IC cards replaced such a handset device.